There's no sign of U.S. abortion law changing anytime soon, but Alabama wants to be ready if it ever does.

A proposal in the Republican-controlled Legislature would declare Alabama a "right to life" state by amending the state constitution. The House of Representatives will vote on the bill Thursday, and if it passes the Legislature and is signed by the Republican governor, the constitutional amendment would go before voters in 2018.

Opponents believe Republicans are just trying to put a largely symbolic anti-abortion referendum on the ballot the same year lawmakers are up for re-election. But there is optimism among conservatives that Roe v. Wade, the 1973 law establishing a women's right to an abortion, could be overturned now that President Donald Trump is in power.

Trump has said he would appoint justices open to overturning Roe v. Wade and nominated conservative judge Neil Gorsuch to replace the late Justice Antonin Scalia. Because of the age of some of the justices, many believe Trump may get another appointment during his presidency, perhaps giving the court a conservative majority for the first time in decades.

"We want to make sure that at a state level, if Roe v. Wade is overturned, that the Alabama Constitution cannot be used as a mechanism by which to claim that there is a right to abortion," said state Rep. Matt Fridy, the legislation's sponsor.

The proposed constitutional amendment says it would be Alabama's public policy "to recognize and support the sanctity of unborn life and the rights of unborn children, most importantly the right to life."

Fridy disputed any notion that politics were at play and said Alabama is "a pro-life state." Trump easily won Alabama in November with 62 percent of the vote.

Other states such as Missouri and Utah have approved similar "right to life" measures.

Planned Parenthood representatives said the Alabama proposal is a "trigger law" aimed at quickly changing abortion access in the state if Roe is overturned.

"The net impact is that it would completely outlaw abortion access in the state of Alabama regardless of the situation. It is total ban," said Katie Glenn, the Alabama director of Planned Parenthood Southeast.

Added Nikema Williams, vice president of Planned Parenthood Southeast: "I don't think it can be overlooked that this is again playing politics with women's health to drive turnout in 2018."

The Alabama legislation is backed by Republican leadership in the House and is part of a slate of "pro-life day" bills up for debate.

In the past five years, Alabama lawmakers have pushed a slate of abortion restrictions that have been blocked by federal courts, including a ban on the most commonly used second trimester abortion procedure. A federal judge also blocked in October enforcement of a law that would have banned abortion clinics within 2,000 feet of K-8 public schools.

In June, the Supreme Court issued its most important abortion decision in many years, striking down restrictions in Texas that required doctors who perform abortions to have admitting privileges at nearby hospitals and forced clinics to meet hospital-like building standards. The court held that placed an "undue burden" on women seeking abortion because it would force the closure of many clinics.

In the future, the court is likely to face the question of whether other types of abortion restrictions impose an undue burden. One example: laws adopted by numerous states that ban most abortions after 20 weeks of gestation on the disputed premise that a fetus can feel pain at that stage.